ANALYSIS OF CAPACITANCE-VOLTAGE CHARACTERISTICS OF SI1-XGEX SI QUANTUM-WELL STRUCTURES/

The theoretical expressions of the capacitance-voltage (C-V) character istics of a single quantum well are derived in different bias voltage regions based on solving analytically Poisson's equation. A method to determine the parameters, including the doping concentrations in the w ell and the barrier, the location of the well, and the thickness of th e cap layer, as well as the band offset at the heterointerface from an experimental C-V curve is presented. By carefully constructing a test ing sample with the structure of the Al/(thin nitride layer)/Si/Si0.67 Ge0.33/Si Single quantum well, the measurement of a complete C-V curve in a wide voltage range is achieved. The structural parameters of the quantum well derived from the measured C-V curve agree well with the nominal values set by the experimental growth conditions.